Bazin started to write about film in 1943 and was a co-founder of the renowned film magazine Cahiers du cinéma in 1951, along with Jacques Doniol-Valcroze and Joseph-Marie Lo Duca. Bazin was a major force in post-World War II film studies and criticism. He edited Cahiers until his death, and a four-volume collection of his writings was published posthumously, covering the years 1958 to 1962 and titled Qu'est-ce que le cinéma? (What is Cinema?). A selection from this collection was translated into English and published in two volumes in the late 1960s and early 1970s. They became mainstays of film courses in the English-speaking world, but were never updated or revised. In 2009, the Canadian publisher Caboose, taking advantage of more favourable Canadian copyright laws, compiled fresh translations of some of the key essays from the collection in a single-volume edition. With annotations by translator Timothy Barnard, this became the only corrected and annotated edition of these writings in any language.[2]

The long-held standard and highly reductive view of Bazin's critical system, now being subjected to more sophisticated analysis by Bazinian scholars worldwide,[citation needed] is that he argued for films that depicted what he saw as "objective reality" (such as documentaries and films of the Italian neorealism school) and directors who made themselves "invisible" (such as Howard Hawks). He advocated the use of deep focus (Orson Welles), wide shots (Jean Renoir) and the "shot-in-depth", and preferred what he referred to as "true continuity" through mise-en-scène over experiments in editing and visual effects. This placed him in opposition to film theory of the 1920s and 1930s, which emphasized how the cinema could manipulate reality. The concentration on objective reality, deep focus, and lack of montage are linked to Bazin's belief that the interpretation of a film or scene should be left to the spectator. He watched film as personally as he expected the director to undertake it. His personal friendships with many directors he wrote about also furthered his analysis of their work. He became a central figure not only in film critique, but in bringing about certain collaborators, as well. Bazin also preferred long takes to montage editing. He believed that less was more, and that narrative was key to great film.

Bazin, who was influenced by personalism, believed that a film should represent a director's personal vision. This idea had a pivotal importance in the development of the auteur theory, the manifesto for which François Truffaut's article, "A Certain Tendency of the French Cinema", was published by his mentor Bazin in Cahiers in 1954. Bazin also is known as a proponent of "appreciative criticism", the notion that only critics who like a film should review it, thus encouraging constructive criticism.

The André Bazin Special Issue, Film International, No. 30 (November 2007), Jeffrey Crouse, guest editor. Essays include those by Charles Warren ("What is Criticism?"), Richard Armstrong ("The Best Years of Our Lives: Planes of Innocence and Experience"), William Rothman ("Bazin as a Cavellian Realist"), Mats Rohdin ("Cinema as an Art of Potential Metaphors: The Rehabilitation of Metaphor in André Bazin's Realist Film Theory"), Karla Oeler ("André Bazin and the Preservation of Loss"), Tom Paulus ("The View across the Courtyard: Bazin and the Evolution of Depth Style"), and Diane Stevenson ("Godard and Bazin"). Introductory essay, "Because We Need Him Now: Re-enchanting Film Studies Through Bazin," written by Jeffrey Crouse.